1. Field of the Invention
This invention relates to a new and improved street sweeper and more particularly to a new and improved hydraulically operated system for operating the various components of the street sweeper including such components as the side brooms, the conveyor, and the like.
2. Description of the Prior Art
Fixed displacement or variable displacement hydraulic pumps driving fixed displacement hydraulic motors to rotate main brooms, side brooms, and conveyors, have been commonly used on street sweepers for a number of years.
A flow divider has been commonly used to split the hydraulic flow from a single pump and direct the flow to two or more hydraulic motors for driving rotating sweeping components.
Variable displacement hydraulic pumps which are hydraulically pressure-flow compensated to provide a single constant output in gallonage within a given range of input speeds also have been known for a number of years.
Manually controlled variable displacement hydraulic pumps have been used to obtain a desired output in gallons per minute even though the input speed is constantly changing.
The H. M. Rush U.S. Pat. No. 2,833,116 discloses the use of a hydraulic drive providing a constant rotating speed of the sweeping elements while the power input source turns at a variable speed to propel the vehicle.